Heat exchange device



Dec. 8, 193 1. McKEE 1,835,074

HEAT EXCHANGE DEVICE Filed April 25, 1929 s Sheets-Sheet 1 INVENTOR Fg-jARTHUR 6- NEAEF AT ORNEY Dec. 8, 1931. A. G. M KEE HEAT EXCHANGE DEVICE:5 Sh eets-Sheet 2 Filed April 25, 1929 Imam & I 1

INVENTOR AFT/1U}? 6. MFA/E5 wmrnm AT FORNEY Dec.v 8, 1931. A. G. M KEEHEAT EXCHANGE DEVICE Filed April 25, 1929 3 Sheets-Sheet 5 Patented Dec.8, 1931 UNITED STATES ARTHUR G. McKEE, or CLEVELAND, c1110 HEAT nxcrmnennnvrcn Application filed April 25,

This invention relates to heat exchange devices of the class in which aplurality of loosely assembled members are alternately heated to hightemperatures and cooled.

through'a considerable temperature range by contact of gases therewith.It involves anew and improvedmeans of and method for supporting suchmembers whereby the expansion and contraction of the members take placewithout setting up any serious lateral or vertical strains, and forpreventing harmful or destructive stresses on the members of the device.

One adaptation blast stove.

Herctofore, so far as I am aware, hot blast stoves have been constructedas .follows:

A circular or elliptical combustion chamber was built inside the stoveshell. It rested on the bottom ofthe shell and was tied into thebrickwork lining of the shell from its lower end up to the top of thecheckwork. A plurality-of closely spaced brick piers rested on thebottom of the stove shell outside. of the combustion chamber andsupported on their tops a plurality of horizontally arranged brickarches tied together and to the circular brick wall inside the shell ofthe stove. These arches in turn carried on their tops other smallerhorizontally arranged brick arches at right angles to the first archesof my invention is a hot and similarly tied into each other, the archestherebeneath, the lining of the stove, and the combustion chamberwalls.Flat fire bricks or tiles spanned the spaces above the second arches andwere spaced apart distances corresponding to the spacing of the checkersor tiles thereon. .Circuitous and more or less restricted gas passageswere thus provided through the arches and between the bricks to thecheckers. The'checker brick or tile were built on these flat bricks ortiles to the desired height. 2

There are many disadvantages inherent in; 0 such a construction amongwhich are the following:

To insure adequate support for the checkers during the life of the stovethe supporting structure of piers, arches and fire brick tiles have beenbuilt strongly and tied to- 1929; Serial No. 357,922.

gether into substantially an integral whole, which not only seriouslyimpeded the flow of, gases therethrough by'decr'easing the areaofpassage and interposing angular bends in their line of travel therebyincreasing the losses due to friction and turbulence but also Was illadapted to withstand the wide and sudden temperature changes. Due to thecontraction and expansion incident to the recurrent temperature changesthe support- 0 ing structure often cracked and disintegrated withresultantdestruction of the stove lining. When any such failure occurredthe cost of repair was very high and often required the rebuilding ofthe checkers as well as the supporting structure for the reason that itwas impossible to replace arches with new ones and have them take uptheir share of the superimposed load without first removing thecheckers.

Since the fire brick used in the supporting structures has smallcompressive and almost negligible tensile strength but still must carrythe heavy load of the checkers the volume of the fire brick in thesupports has been increased to such an extent that the areas of thepassages for air and gas were correspondingly decreased to an amountless than was desirable with an incident increase in the frictionalresistance to the movement of the go gases and a very unequaldistribution of the gases. e V

By my invention I am able to provide a heat exchange device, forexample, a hot blast stove in which the supports for the 5 checker workwill last as long as or longer than the balance of the stove; in whichthe gas passages through the supporting structure are as-large. as .orlarger than the checker openings and very direct; in which the disa0.tribution of the gases is'as free as is possible because of directpassages of very largearea in which much stronger supports for the tilescan be built within the' space allotted; in

which ample room can beprovided for ac cess to all supports forinspection, cleaning or. repairs; in which the checkers are sup-' portedin units so that each unit may expand and contract independently of andwithout damage to the others; in which the walls of as may be needed byany of the checker-work units or their supports can be readily madewithout disturbing other similar units or imposing any added weight onsuch other units; and in which practically the entire lower edges orsurfaces of the lowermost horizontal 10 course of checkers or tiles areresting on the supporting means.

In the drawings accompanying and forming a part of this specification inwhich I have illustrated one embodiment of my invention Fig. 1 is afragmentary view of a central vertical section of a hot blast stoveembodying my invention;

Fig. 2 is a top plan View, partly in section, of the stove of Fig. 1,and indicating certain of the supporting members;

Fig. 3 is a top plan view of one form of tile support constructed inaccordance with my invention;

Fig. 4 is an elevation of the tile support being taken from the frontof'Fig. 3;

Fig. 5 is an elevation of the tile support, taken at right angles to theview of Fig. 4:;

F ig. 6 is a perspective vie-wof an improved checkeror tile;

Fig. 7 is an enlarged top plan View of several assembled tiles;

Fig. 8 is a top plan view;

Fig. 9 is a side elevational view partly in section of part of amodified form of tile ,support;

Figs. 10 and 11 are top plan and side elevational views of another partof the modified form of tile support;

Fig. 12 is an enlarged sectional view taken .on line 1212 of Fig. 10;and

Fig. 13-is a sectional View of a tile from the bottom course; 2

Fig. 1 1 is a side el evation partly in section taken on line 1414 ofFig. 15 of a hot blast stove of the central combustion chamber typeembodying my invention;

Fig. 15 is ahorizontal sectional view taken on line 15 15 of Fig. 14;and

Fig. 16 is an enlarged fragmentary View showing the details of the beamsupporting strut;

Fig. 17 is a diagrammatic showing of temperature controlling means for ahot blast stove.

Figures 1 to 16 inclusive show a hot blast stove of a more or lessconventional type comprising an outer shell 1 with suitable lining walls2. A combustion chamber 3 is formed by walls 4 which rest on the bottomwall of the shell 1 and are spaced apart from the lining walls 2. Thisstove 1 is provided with an inlet 5 for gases to be burned in chamber 3,with one or more outlets 6 for the escape of gaseous products ofcombustion flowing from chamber 3 and with a suitable passage 7 throughwhich heated air may flow when the stove is reversed and air to beheated is brought in through passages 6.

To support the checkerwork within the stove shell and outside of thecombustion chamber 3 I provide supporting members so constructed andsupported as to be independent of each other, and each being free toexpand and contract vertically and laterally without contacting with theothers. Preferably such members take the form of a plurality ofsupporting columns or posts 8 which rest on the bottom wall of theshell 1. These posts are preferably cylindrical, hollow castingscomposed ofmetals or alloys resistant to the gases which contacttherewith and having sufiiciently high compressive and tensile strengthsat the highest temperatures to which they are subjected to support theloads imposed thereon. For example, cast iron, chromium steel orchromium nickel steel and their alloys may be used for these posts.

N on-metallic materials may be used for coling throughout the spacewithin the lining 2 and outside of the combustion chamber walls 4.

Each cap 9 is independent of all the other caps and together with itspost 8 forms a supporting unit for checkers or tiles disposed thereabovewhich is free to expand and contract vertically and laterallyindependently of the other units. The cap of Figs. 3, 4 and 5 consistsof a cylinder 10 having an annular flange 11 at its lower end to locatethe cap on the topof a post 8; a grid or perforated plate 12 at theupper end and webs or ribs 12a from the cylinder 10'to the under side ofthe plate 12 between the round openings 13 or square openings 13a in theplate. Since some of the openings 13 and 13a are above the post 8 andannular flange 11, enlarged openings 14 are provided through sides ofcylinder 10 and webs 12a to permit gas to flow through such openings 13and 13a.

The-caps 9 are preferably composed of cast metal but since they aresubjected to greater tensile stresses than the posts 8 and also tosubstantially the same compressive stresses it is preferable to usemetal compositions such plate 12 and with the round holes 16 through thetiles aligned with passages 13 in the plate. Raised ribs 12?) on theplate about the openings serve to position the tiles of the lowestcourse on the plate. The tiles of the lowest course are chamfered aroundthe bottom of the central hole 16, as indicated at 16a, Fig. 13, to fitthe ribs 12?), Fig. 4., or 23a, Fig.12, as the case may be. Additionalcourses of checkers or tiles 15 are similarly supported on the firstcourse and other courses are added until the desired vertical height ofcheckerwork has been attained. The tiles 15 are preferably not bonded toeach other nor otherwise connected together, and are not connected tothe lining walls 2 or walls 4, and the caps 9 are also not connected towalls 2 or 4 or to each other. The tiles are laid without beingcrowdedclosely together, thus leaving each tile as well as eachgroupfree to expand slightly in a horizontal direction withoutdestructive contact with its neighbor and also free to expandvertically. As a result each post or column 8 and its cap 9 supports thegroup of tiles covering a given area and extending to the full height ofthe heat exchanging space, and each such group may be considered as aunit or member which can ex- ,pand and contract laterally and verticallywithout any destructive contact withthe adjacent groups or members orthe walls 2 or 4, and which can be repaired, replaced or renewed whollyor in part or cleaned independently of the other unitsor members.

The entire weight of each such unit is transmitted by its column 8 tothe stove foundation.

The tiles 15 (see Fig. 6) are preferably octagonal in horizontal sectionwith their alternate outer side surfaces 15a wider than the remainingside surfaces 15?) so that when the tiles are assembled as abovedescribed with the narrower surfaces 15?) of adjacent tiles in contactwith each other, the wider surfaces 15a define square passages 17between the tiles which align with the corresponding square passages 13ain plate 12. In this manner the tile walls define round holes 16 andpassages 17 are formed between the tile of the maximum desired size fromthe standpoint of eflicient stove operation and at the same time thewalls of the tiles are kept at the desired minimum thickness. It will bereadily understood that tiles of exactly octagonal form or of any othersuitable forms may be used.

In Figs. 8 to 12 is shown a modified form of cap which is made up of twoseparable parts. One part, which I have named a column cap, comprises adisc 18 to seat on the top of a column 8 and a depending flange 19 tolocate the disc on the column, and a plurality of upstanding ribs 20united to the disc and flange and to each other and terminating at theirtops in the same horizontal plane. At the intersection of certain of thewalls 20, holes are formed to receive dowel pins 20a which project upinto a-nd serve to locate the separable grid or plate 21 on the columncaps.

Certain parts of the ribs 20 are cut away at 20b to form gas passages.The grid or plate 21 resembles the plate portion 12 of the cap of Figs.3, 4 and 5 but has shallow strengthening ribs 22 integral with theunderside of the plate and extending between the perforations 23., and23a. Tile locating ribs 23?), similar to the ribs 12b, Fig. 4, projectabove the top of plate 21.

The columns 8 and caps are so designed that the center of thesuperimposed load of tiles,

is, in each case, approximately on the center of the column, thusavoiding any eccentric loading of the columns 8.

The columns 8 are so located in the stove shell that when the columnscaps 12 or caps and grids, 20 and 21, respectively, are assembled, themarginal projections and recesses match in such a manner as to formsquare openings 13a or 23a between them. In assembling, clearance isalso allowed between adjacent marginal projections of the grids. Supportis thus provided for all the tiles and space is allowed for freeexpansion or contraction of the grids.

The column caps and grids of Figs. 8 to 12 arepreferably made of somematerial suc as mentioned for caps 9.

In addition to the above mentioned advantages my invention enables me,without increasing the height of the stove, to increase the amount ofheat exchanging capacity of a hot blast stove by an amount correspondingto the additional layers of checker tile which I employ in the spaceheretofore occupied by the several arches and bridgespf the checker worksupporting means in prior art hot blast stoves, this being accomplishedby the relatively small vertical dimensions of the caps as compared withthe much greater vertical dimensions required by the prior art archesand bridges. I also obtain a larger amount of heating surface due to thesmaller openings and thinner walls of the checkers, the use of suchchecks being, made possible by supporting the entire bottom ends of thechecker walls on a rigid, nondistorting structure.

The impro ed construction above described with its capacity for beingrapldly and highly heated is well adapted to use with temperatureindicating and controlling means. In fact it is desirable to employ somesuch means to prevent abnormally high temperatures in the spacesurrounding the supporting means, such as the columns and capsillustrated.

In Fig. 1 is shown a pyrometer tube 25, which may be of any suitableform and construction, and which projects into the stove space in whichthe columns 8 are located. A temperature indicator or recorder 26disposed outside of the stove shell 1 is connect-v ed to the pyrometer.An attendant may regulate the temperature in the stove as desired byobserving the indicator or recorder and control the combustible gasaccordingly.

Figs. 1 and 2' show a hot blast stove with the combustion chamberadjacent to one side wall. In Figs. 14 to 16 I haveshown a-stove' inwhich the combustion chamber is centrally disposed in the shell.Conduits leading from outside the shell to the combustion chamber arerequired with such a construction but would interfere with certain ofthe checkerwork supports of Figs. 1 and 2 unless rovision is made forsupporting the cliec erwork over the conduits in some other manner.

In Figs. 14 to 16, the stove shell 1 a lining 2, a combustion chamber 3,checkerwork 4, posts 8 and caps 9 for supporting checkerwork 15.Conduits 30 extend from the outside of shell 1 to chamber 3 and affordpassageways for combustible gas to enter the combustion chamber or forair blast to enter or leave the stove. Outlets 31, similar to outlets 6of Fig. 1, permit escape of products of combustion and entry or escapeof air blast.

The conduits 30 are formed by brickwork. I have extended the brickworkat either side of each conduit, as at 32, to formv piers. On each pieris placed a metal plate 33 having a knife edge recess 34 in its .uppersurface. Knife edge members 35 rest in recesses 34 and carry beams 36recessed at 37 to receive the members 35. The beams 36 each carry a cap9 and serve as substitutes for posts 8 to support caps 9 over conduits30. If desired, one knife edge 35 may be eliminated by continuing thepier 32 on up until plate 33 contacts with beam 36 when the latter is inits normal position.

In erecting the apparatus of Figs. 14 to 16 the posts 8 and caps 9 areput in place, then beam 36 is rested on members 35 and held in placeuntil cap 9 is lowered onto beam 36 after which wedges may be insertedbetween cap 9 on beam 36 and adjacent caps 9. Then the checkerwork canbe laid and the Wedges can then be removed. The members 35 will permitfree expansion and contraction of beam 36 while adjacent caps 9 willprevent any dislodgment of members 35.

In Fig. 17, which shows means for automatically regulating thetemperature of a hot blast, 40 designates a valve in the conduit 5 ofFig. 1 for varying the amount of combustible gas admitted to thecombustion chamber 3. 41 designates a motor actuating device of any wellknown type for actuating valve 40. The thermostat 25 and indicator 26 ofFig. 1 are connected by any suitable well known electrical meansto themotor device 41 so that when the temperature in the space surroundingposts 8 reaches a predetermined temperature the valve 40 will beactuated to decrease or cut ofl' the supply of combustible gas andthereby prevent further rise in temperature. When the temperature fallsbelow the predetermined temperature the valve 40 will be opened to admitmore combustible gas. In this manner the temperature about posts 8 canbe controlled as desired.

Having thus described my invention what I desire to secure by LettersPatent is defined in what is claimed, it being understood that variouschanges, modifications and alterations may be made in the abovedescribed embodiment of my invention without departing from the spiritand scope of the invention.

What isclaimed is: l,

-1. A stove checker supporting structure com osed of independent units,free to move vertically, independent of each other, and provided withexpansive clearance laterally, each resting on a unit supportindependent and free of contact with the adjacent supporting units.

2. Stove checker supporting units, each comprising a single columnsupporting a concentrically loaded cap out of contact with adjacentsupporting members.

3. A stove checker supporting structure including a plurality of units,each unit of which is composed of a gas and heat resistant metal ofadequate strength at stove temperatures to carry the load of tilessuperimposed thereon and supporting practically the entire bottomsurface of the bottom course of checker tiles, each unit being centrallysupported on a column, independently of the adjacent supportingstructures and brickwork.

4. A hot blast stove comprising a lined shell, a combustion chambertherein and a plurality of vertical groups of checkers each group beingindependently supported without supporting contact with adjacent groups,the said shell, shell lining, chamber and groups forming structurallyindependent units capable of individual expansion and contractionwithout destructive engagement with adjacent units.

5. In a hot blast stove, a heat exchanging unit comprising a column, acolumn cap and a plurality of checkers arranged vertically above andsupported by the column and its cap arranged to permit unrestrainedexpansive and contractive movement.

6. In a hot blast stove, a column, a perforated cap seated 011 thecolumn and supported solely thereby, and a plurality of hollow checkerssupported on the cap and arranged to define passages aligned verticaL lywith the perforations in the cap.

7. In a hot blast stove, a plurality of independent, adjacent, uprightgroups of superimposed checker tiles defining vertical gas passages, anda plurality of means each supporting one of said groups for expansionand contract-ion of each group independent of the remaining groups. 8.In a hot blast stove, a plurality of independent adjacent, uprightgroups of superimposedchecker tiles defining vertical gas passages, anda plurality of means each supporting one of said groups for expansionand contraction of each group independent of the remaining groups, thesaid means having vertical perforations aligned with the said passages.

9. In a hot blast stove, a plurality of in"- dependent supportingcolumns resting on the stove foundation, and a plurality of groups ofadjacent superimposed checker tiles, each group being supported by acolumn for expansion and contraction independently oftheremaininggroups.

10. A hot blast stove including checkerwork composed of independent,vertically extended groups of units, and means supporting each entirelyindependently of other such groups. 0

11. A hot blast. stove including a lined stove shell and a plurality ofgroups of adj acent vertically extending columns of checkerwork units,each group of units being spaced apart from adjacent groups and beingsupported independently of such other groups.

12. A hot blast stove comprising a lined stove shell, a combustionchamber within the shell, and a plurality of vertically extended groupsof 'checkerwork units within the shell, each supported on a column meansresting on the bottom wall of the shell and being independent of andspaced apart from other such groups of units and from the shell lining'for independent expansion and contraction. l 4

13. A hot blast stove comprising a liiied stove shell, a combustionchamber therein having its wallssu ported on the bottom wall of theshell an spaced apart from the lining of the shell for independentexpansion and contraction, and a plurality of vertically extended groupsof checkerwork units within the shell, each group of units beingsupport-- ed on a column res'tmg on the bottom wall of the shell andbeing independent of and spaced apart from other such groups of units,and from the combuflion chamber walls and from the shell lining forifidep'endent expansion and contraction.

14. In a hot blast stove, a column, a perj forated cap on the column,and a horizontal .course of upstanding hollow checkers supported on t ecap with substantially their entire lower surfaces engagin 1 the cap andwith their passages aligned wit perforations in the cap.

15. In a hot blast stove, a horizontal course of checker tiles definingvertical as passages, and column means supporting y engagingsubstantially the entire lower surfaces of said tiles, said means havingperforations in alignment with and at least as large as the said gaspassages. Y

16. In aihot last stove, a horizontal course of checker tiles definingvertical gas passages,

and column means of substantiall the same horizontal extent as thecourse 0 tiles supporting the tiles and having perforations msubstantially vertical alignment with the said chamber Walls, and aplurality of disconnected means each supporting a portion of the saidtiles independently of the remaining tiles and supporting means.

18. In a. hot blast stove, a plurality of independent chcckerworksupporting units,

each unit being free to expand and contract laterally and verticallywithout contacting with any of the other units.

19. In a blast furnace stove, a plurality of columns and column caps forsupporting the checkerwork so constructed and su ported as to beentirely independent 0 each other and each being free to expand andcontract vertically and laterally without con- Y tacting with the othercolumns or caps.

20. In a hot blast stove, a central combustion chamber having inlet andoutlet. conduits, checkerwork above said conduits and means forsupporting the checkerwork in independent groups, said means including abeam extending across one of the conduits carrying a grou of checkerworkand supported by expansion and contraction permita tin means.

n testimony whereof I hereunto aiiix my signature this'23d da of A ril,1929. A THU G. MCKEE.

